renaming net interfaces sometimes gives "renameX" names

[Patrick Domack]

I have been having problems, and some others have to, with 14.04 devbiosname causing renaming of network interfaces.

I also started to have this issue today on 12.04

In both cases ethx gets renamed to renamey interface, and causes the interface to basically get lost.

In my 12.04 case, I started with two nics, eth0 and eth1, then added a third as eth2, and removed eth0 from the system.

This caused eth0 to be renamed to eth1, and eth1 to be renamed to eth2.

Just now, this started failing, and eth0 gets renamed to rename3, and eth1 stays as eth1. and boot fails due to no network.

for 14.04, the same type of issue, eth0 gets renamed to rename2, and eth1 gets renamed to whatever it should (em2, p5p1, ...)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Kees (kees2014)]

I'm experiencing the same: after a reboot p5p2 was renamed to 'renamed3' which is not in /etc/network/interfaces. This causes the server to be unreachable.

[Martin Pitt (pitti)]

I sent a proposal to https://lists.ubuntu.com/archives/ubuntu-devel/2015-May/038761.html which will fix this. Within the boundaries of the existing persistant net generator there isn't much that we can do, I'm afraid; it's an inherent design flaw.

[Martin Pitt (pitti)]

When using the old-style /etc/udev/rules.d/70-persistent-net.rules schema this is an unavoidable race condition. Our udev package has a patch to try and make the best of it (http://anonscm.debian.org/gitweb/?p=pkg-systemd/systemd.git;a=blob;f=debian/patches/Revert-udev-network-device-renaming-immediately-give.patch) but it can only help so far.

Since Ubuntu 15.10 we use a different schema for persistent names which entirely avoids this race condition. So if this still happens, I suggest removing 70-persistent-net.rules and adjusting your configuration to the new schema, as documented in /usr/share/doc/udev/README.Debian.gz .